1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. |
4 | */ |
5 | |
6 | #include <linux/module.h> |
7 | #include <linux/of_address.h> |
8 | #include <linux/platform_device.h> |
9 | #include <linux/thermal.h> |
10 | |
11 | struct thermal_mmio { |
12 | void __iomem *mmio_base; |
13 | u32 (*read_mmio)(void __iomem *mmio_base); |
14 | u32 mask; |
15 | int factor; |
16 | }; |
17 | |
18 | static u32 thermal_mmio_readb(void __iomem *mmio_base) |
19 | { |
20 | return readb(addr: mmio_base); |
21 | } |
22 | |
23 | static int thermal_mmio_get_temperature(struct thermal_zone_device *tz, int *temp) |
24 | { |
25 | int t; |
26 | struct thermal_mmio *sensor = thermal_zone_device_priv(tzd: tz); |
27 | |
28 | t = sensor->read_mmio(sensor->mmio_base) & sensor->mask; |
29 | t *= sensor->factor; |
30 | |
31 | *temp = t; |
32 | |
33 | return 0; |
34 | } |
35 | |
36 | static const struct thermal_zone_device_ops thermal_mmio_ops = { |
37 | .get_temp = thermal_mmio_get_temperature, |
38 | }; |
39 | |
40 | static int thermal_mmio_probe(struct platform_device *pdev) |
41 | { |
42 | struct thermal_mmio *sensor; |
43 | int (*sensor_init_func)(struct platform_device *pdev, |
44 | struct thermal_mmio *sensor); |
45 | struct thermal_zone_device *thermal_zone; |
46 | int ret; |
47 | int temperature; |
48 | |
49 | sensor = devm_kzalloc(dev: &pdev->dev, size: sizeof(*sensor), GFP_KERNEL); |
50 | if (!sensor) |
51 | return -ENOMEM; |
52 | |
53 | sensor->mmio_base = devm_platform_get_and_ioremap_resource(pdev, index: 0, NULL); |
54 | if (IS_ERR(ptr: sensor->mmio_base)) |
55 | return PTR_ERR(ptr: sensor->mmio_base); |
56 | |
57 | sensor_init_func = device_get_match_data(dev: &pdev->dev); |
58 | if (sensor_init_func) { |
59 | ret = sensor_init_func(pdev, sensor); |
60 | if (ret) { |
61 | dev_err(&pdev->dev, |
62 | "failed to initialize sensor (%d)\n" , |
63 | ret); |
64 | return ret; |
65 | } |
66 | } |
67 | |
68 | thermal_zone = devm_thermal_of_zone_register(dev: &pdev->dev, |
69 | id: 0, |
70 | data: sensor, |
71 | ops: &thermal_mmio_ops); |
72 | if (IS_ERR(ptr: thermal_zone)) { |
73 | dev_err(&pdev->dev, |
74 | "failed to register sensor (%ld)\n" , |
75 | PTR_ERR(thermal_zone)); |
76 | return PTR_ERR(ptr: thermal_zone); |
77 | } |
78 | |
79 | thermal_mmio_get_temperature(tz: thermal_zone, temp: &temperature); |
80 | dev_info(&pdev->dev, |
81 | "thermal mmio sensor %s registered, current temperature: %d\n" , |
82 | pdev->name, temperature); |
83 | |
84 | return 0; |
85 | } |
86 | |
87 | static int al_thermal_init(struct platform_device *pdev, |
88 | struct thermal_mmio *sensor) |
89 | { |
90 | sensor->read_mmio = thermal_mmio_readb; |
91 | sensor->mask = 0xff; |
92 | sensor->factor = 1000; |
93 | |
94 | return 0; |
95 | } |
96 | |
97 | static const struct of_device_id thermal_mmio_id_table[] = { |
98 | { .compatible = "amazon,al-thermal" , .data = al_thermal_init}, |
99 | {} |
100 | }; |
101 | MODULE_DEVICE_TABLE(of, thermal_mmio_id_table); |
102 | |
103 | static struct platform_driver thermal_mmio_driver = { |
104 | .probe = thermal_mmio_probe, |
105 | .driver = { |
106 | .name = "thermal-mmio" , |
107 | .of_match_table = thermal_mmio_id_table, |
108 | }, |
109 | }; |
110 | |
111 | module_platform_driver(thermal_mmio_driver); |
112 | |
113 | MODULE_AUTHOR("Talel Shenhar <talel@amazon.com>" ); |
114 | MODULE_DESCRIPTION("Thermal MMIO Driver" ); |
115 | MODULE_LICENSE("GPL v2" ); |
116 | |